Heavy gunfire was heard Monday from inside an airbase in northern India as security forces tried to hunt down militants who attacked the facility on the weekend, officials said.
At least seven soldiers and four gunmen have been killed in the fighting that erupted at the air force station at Pathankot early Saturday.
The search at the base continued overnight and at least one of the attackers was still alive, local police said.
"After intermittent gun-fire through the night, there was a lull for a few hours. Now, we are hearing heavy gunfire from inside the complex since the morning," an area police officer said from the scene, requesting anonymity.
"It appears the security forces are engaged in neutralizing the attackers. Helicopters are also deployed to assist the offensive," he said over the phone.
The search operations could continue for many more hours as the air force station sprawls across 14 square kilometres.
Top Indian officials were tightlipped on the operation. "Nothing new on it so far. The status is the same as it was yesterday," federal Home Minister Rajnath Singh said.
Indian intelligence agencies said that a group of five to seven militants had infiltrated from Pakistan to carry out the attack.
The security forces had secured air force assets - fighters and attack helicopters - by confining the gunmen to the periphery of the air force station.
The attack came over a week after Indian Prime Minister Narendra Modi visited Pakistan to give a push to peace talks between the rival neighbours.
The nuclear-capable South Asian states have fought three wars, two of them over the disputed Kashmir region.
Delhi blames Islamabad for aiding militant groups. Pakistan, which rejects the charge, has condemned the airbase attack.
The next round of talks between the foreign secretaries of the two countries is scheduled to be held in Islamabad in mid-January.
On Sunday evening, Modi chaired a meeting with top officials to discuss the situation while Foreign Minister Sushma Swaraj also met diplomats to chalk out a strategy on Pakistan, broadcaster NDTV reported.
Five security personnel who were part of the corps which guards defence installations and a commando with the air force were among those who died during the operation. Twenty more were injured.
Funerals of security personnel were being held on Monday with state honours. Scores of people poured in to pay tribute to them.